Final answer:
The best production method would be the one with the lowest total cost. In this case, Method 1 would be the best production method.
Step-by-step explanation:
The total cost of each method can be calculated by multiplying the cost of labor per unit by the number of units of labor, and adding it to the cost of capital per unit multiplied by the number of units of capital. For Method 1, the total cost would be $6,000 ($100/unit of labor x 50 units of labor + $400/unit of capital x 10 units of capital). For Method 2, the total cost would be $8,000 ($100/unit of labor x 20 units of labor + $400/unit of capital x 40 units of capital). For Method 3, the total cost would be $7,000 ($100/unit of labor x 10 units of labor + $400/unit of capital x 70 units of capital).
The best production method would be the one with the lowest total cost. In this case, Method 1 would be the best production method since it has the lowest total cost. If the cost of labor rises to $200/unit, the company should still use Method 1 because it would still have the lowest total cost compared to the other methods.